1. Field of the Invention
This invention relates generally to liquid dispensing systems and more particularly to cartridge-type flow control valves for use in public drinking fountains.
2. Description of the Prior Art
There are a number of shut-off type control valves for use in drinking fountains known in the prior art. Among them is a control valve taught by Homeyer in the U.S. Pat. No. 3,003,519. Homeyer teaches a rather complicated valve wherein when the push-bottom is pressed the valve stem is driven downward to create a gap between the valve head and the valve seat. Homeyer relies on a diaphragm to divide the upper portion of the valve from the lower portion with the valve stem extending therethrough.
U.S. Pat. No. 3,166,500 to Noakes et al teaches a drinking water cartridge valve which incorporates the use of a ball valve element. The valve is actuated by driving the valve stem downward to displace the ball from the valve seat.
U.S. Pat. No. 3,493,010 to Dreibelbis teaches a valve cartridge wherein the valve stem is used to drive the valve head downwards so that it disengages from the seat thus allowing water to flow through the valve. Dreibelbis further incorporates a diaphragm defining the upper and lower portions of the valve.
Yet another cartridge type control valve is depicted in U.S. Pat. No. 3,902,600 to Turner et al. It's design and operation is similar to those previously discussed. There is a diaphragm through which a valve stem extends. Pressing down on that valve stem causes the valve head to disengage from the seat allowing the water to flow.
Still another cartridge control valve is taught in the U.S. Pat. No. 4,576,195 to Dreibelbis. It includes a cup like member having an elastomeric diaphragm through which the valve stem extends. As within some of the other designs discussed above, driving the valve stem downward causes the valve head to displace from the valve seat.
None of the references teach a monolithic bottom wall component having incorporated therein both the inlet and outlet nozzles as well as a transverse leg component for delivering fluid from the fluid transfer chamber to the outlet nozzle. Further, none of the references teach a valve stem having O-rings adjacent to the valve bore to provide sealing of the valve stem within the valve bore without the need of a diaphragm. Further none of the references cited teach a housing member which receives the housing of the fluid transfer chamber and provides a water reservoir between the inlet nozzle and the fluid transfer chamber. Also, none of the references cited teach a valve stem cap which has an integrally formed coiled plastic section to aid in bringing the valve head back to seated position when pressure is released on the valve stem.